Another solution -- without flip flops this time !!

Clocked RS latches modified for edge triggering on the clock can be

cascaded -- would take N latches and you can pick off your output anyplace

along the chain to get any desired duty cycle. A clocked RS latch expands to

5 gates, and you'll probably need 2 or 3 more to make it edge triggered,

which gets you riight up there with the flip flop for gate count per stage,

but with the disadvantage of not using a counter approach which means many

more stages for larger N.

The question then becomes "just exactly HOW PURE" must the combinatorial

logic be. If you cant build latches or flipflops from gates, I dont think

its possible.

Just for grins -- here is a weird way to do it that just uses low level

gates + some analog components

http://www.wenzel.com/pdffiles/dividers.pdf